The present invention relates to a device for forming a reinforcing layer of a decay-retarding agent on the surface of a tooth by exposing the latter to ultrasonic waves in the presence of a decay-retarding agent.
In order to retard tooth decay, it is known to manually coat the surface of the tooth with a decay-retarding agent such as tin fluoride, sodium fluoride, or fluoroamine. However, if reliance is made only on such a coating to retard tooth decay, the results are not satisfactory inasmuch as such a coating has only a poor capability of adhering to a tooth and is dissolved away in a relatively short time. Thus, with such procedures it is impossible to achieve a lasting effect for the decay-retarding agent. Furthermore, even while a coating of a decay-retarding agent remains on the surface of a tooth, the capability of preventing calcium from dissolving out from the tooth surface is extremely poor.
Since the method for forming a reinforcing layer of a decay-retarding agent on the surface of a tooth by radiation of ultrasonic waves in the presence of the decay-retarding agent is based on the novel finding, there has not been known a suitable device or tool for practising this method appropriately.
Some of us has already proposed a method in which a ultrasonic vibrator as a ultrasonic wave-generating member is disposed in a tray having a U-shaped section, a tooth decay-retarding agent is coated in advance on the surface of a tooth to be treated, the tray is capped on the coated tooth, and then ultrasonic waves are radiated to effect the treatment. According to this method, however, if a ultrasonic wave transmitting medium is not filled between the vibrator and the tooth, ultrasonic waves are not transmitted effectively. Accordingly, the treatment has heretofore been conducted while water or the like is kept in the mouth. However, this is very troublesome and the method is not practical. Moreover, the tooth decay-retarding agent is wastefully leaked out during the treatment.